This invention relates to methods and means for utilizing raster input scanners as readers for automatic telephone dialing equipment and, more particularly, to automatic telephone dialing methods and means for facsimile systems and the like.
Facsimile systems have gained widespread commercial acceptance because they offer rapid and accurate, long distance communication of most any type of graphic information (e.g., handwritten and printed pages, charts, graphs, and drawings), subject to minor exceptions which are principally attributable to resolution limitations. As is known, a basic facsimile system comprises a transmitting terminal and a receiving terminal which are interconnected by a communications link. Customarily, there is a raster input scanner within the transmitting terminal for serially converting or remopping the two dimensional information content of an original document (generally called a "subject copy") into a corresponding, one dimensional video signal. Moreover, the transmitting terminal normally includes a modulator for modulating a suitable carrier signal in accordance with the video signal so that a passband signal is provided for transmission to the receiving terminal via the communications link. Accordingly, the receiving terminal typically has a demodulator for recovering the video signal and a raster output scanner for serially printing a more or less exact replica or "facsimile" of the subject copy in response to the video signal.
Dedicated transmitters and receivers are sometimes used as terminals for facsimile systems, but the more common practice is to employ transceivers which are selectively operable in a transmit mode or a receive mode. As a general rule, the communications link or channel for facsimile communications is furnished on demand by a telephone dial system, such as the public switched telephone network.
Substantial effort and expense have been devoted to automating facsimile systems, thereby reducing the amount of operator intervention and supervision required. For example, the Xerox 200 Telecopier transceiver, which is manufactured and sold by Xerox Corporation, operates essentially automatically, with the noteable exception of being able to place outgoing calls. Specifically, that unit automatically answers incoming calls and automatically disconnects incoming and outgoing calls. It can be automatically set in response to remotely generated commands to operate in a transmit mode or a receive mode at any one of its available document transmission rates of two, three, four and six minutes/page. Furthermore, the 200 transceiver includes an automatic document feeder which permits it to sequentially scan a plurality of subject copies automatically when operating in a transmit mode. Additionally, there is a roll fed paper supply which permits that unit to automatically print successive facsimile copies when operating in a receive mode. For a more detailed description of that transceiver, reference may be made to Mason et al. U.S. Pat. No. 3,869,569, which issued Mar. 4, 1975 on a "Facsimile Transceiving Apparatus," and to Perreault et al. U.S. Pat. No. 3,889,057, which issued June 10, 1975 on a "Facsimile Communication System." Hence, those patents are hereby incorporated by reference.
General purpose automatic telephone dialers have been available for several years. Nevertheless, few, if any, facsimile terminals have been equipped with automatic telephone dialing equipment prior to this invention.